W210 - BAS / ASR LIGHT

[mercman01]

Hi All,

Please go easy with me on my first post! - I've tried to read up on this problem before posting but I'm out of idea's now (at least I've tried!).

Basically had the BAS / ASR lamp, handbrake and ABS lamp all come on my way home last night.

After reading forum posts here last night, I went straight to the local Mercedes dealer this morning to buy a brake pedal switch, thinking nice easy fix, well done me!.

Problem is that this has not fixed it fully, the handbrake and ABS lights are out now but the BAS / ASR lamp still comes on and the display says 'display defective'.

I've tried the following:

1. Turning the steering wheel side to side twice, then center it.
2. New battery from a friends car.
3. Starting it with foot on brake and off brake - no difference.
4. Used a generic code reader (ISO mode), displays the car details etc but says no zero fault codes stored.
5. Cruise control works fine.
6. ABS seems to work fine when tested - ie. car didn't skid and you could feel the judder effect.
7. ASR button displays the yellow triangle / exclamation mark when switched off and goes out when switched back on.


Can anyone help me where to look next?.

Thanks!!

 

[television]

Hello and welcome.

The base system is the ABS, the BAS and ESP work on top of the ABS, so ABS lamp on and no ESP-BAS.

The brake lamp switch is the known reason for the BAS-ESP but not for the ABS,,, most ABS faults are sensor related on the wheels.

I think it will need a STAR read out as it sounds now that either the brake lamp switch is still defective or you have a BAS travel sensor fault

 

[mercman01]

Hi, thanks very much for the quick reply.

I've been out in the car 4 times now this evening and covered around 50 miles, no more ABS faults, just this annoying BAS light.

Is it common for new switches from Mercedes to be 'dodgy'? is the design that poor?. Just that buying / trying a 2nd switch is a cheaper option than the last resort of getting it hooked up to someone with STAR.

Is this seen as a MOT failure point?, I know having ABS lights on is now a reason for failure but is this BAS error?.

 

[television]

You still have the old one to try again,,, we do not get many faulty ones, it is mentioned in WIS that the incorrect brake lamp switch can cause it, it gets harder other wise

 

[mercman01]

This will teach me... the old ones in the bin in bits, I took it apart to see what may have failed on it!. I'll pop in to get another one on Monday and try that first. Thanks again.

 

[television]

Sorry there is nothing else that I can add without any fault code

 

[mercman01]

Fixed!!

I had the fault codes read last week, no BAS related codes at all, one for ABS which was cleared. BAS warning light seemed to clear for a while, but then started randomly flickering on and off but still no BAS or ABS codes.

As I was at a bit of a loss now, I went straight to a Mercedes dealer and purchased yet another brake lamp switch, fitted it, and the lamp hasn't come on or even flickered on and off since.

Not that impressed that a brand new switch from a Mercedes dealer seems to have been faulty, but at least it's fixed now, but definitely something to bear in mind if you're having similar issues.